In recent years, a disc-shaped recording medium in which a laser beam of a shorter wavelength is used as a light source, thereby enabling recording and reproduction of a larger capacity has been put into practical use. For example, a blue purple laser which emits a laser beam of a wavelength of 405 nm is used as a light source and a recording capacity of 23 GB (Gigabytes) has been realized by using an optical disc of a one-side single-layer structure.
In recent years, on the other hand, a variety of data formats of video data have been proposed in association with the realization of high fineness of an image in television broadcasting or the like. With respect to each of an encoding/decoding system, a bit rate of data, a frame rate, the number of pixels, an aspect ratio of a display screen, and the like, a plurality of kinds are generally used. In a manner similar to the above, in the case of audio data, with respect to each of bit resolution, an encoding/decoding system, and the like, a plurality of kinds are also generally used.
Further, in a video camera or the like, a method whereby a main video signal of high resolution is outputted and an auxiliary video signal of low resolution is formed on the basis of an image pickup signal has been proposed. The auxiliary video signal is suitable for use in the case where, for example, it is intended to transmit the video signal through a network as soon as possible, in the case of a shuttle operation at the time of searching for a head of a video image by a fast-forward or rewinding operation, or the like.
A video camera constructed in such a manner that the disc-shaped recording medium of the large capacity mentioned above is used, a main video signal of high resolution is outputted, and an auxiliary video signal of low resolution is formed has been disclosed in a Non-Patent Document “AV Watch editing division, “Sony, camcorder or the like using a blue purple laser disc”, “Sony, camcorder or the like using a blue purple laser disc—has been exhibited in NAB 2003 opened on April. A studio recorder and the like have also been exhibited”, [online], Mar. 5, 2003, Impress Corporation, AV Watch homepage (retrieved on Mar. 25, 2003, Internet <URL: http://www.watch.impress.co.jp/av/docs/20030305/Sony.htm>)”.
In such a situation, it is demanded that audio/video data (hereinafter, referred to as AV data) in a plurality of different data formats are allowed to exist mixedly and can be continuously recorded or reproduced onto/from the disc-shaped recording medium of the large capacity mentioned above.
Hitherto, there is not such a technique that the AV data in a plurality of different data formats is mixedly and continuously recorded onto the recording medium, and the AV data in a plurality of different data formats is continuously reproduced and edited from the recording medium on which the AV data in a plurality of different data formats has been mixedly recorded.